1. Field of the Invention
The present invention relates to aquarium filtration systems utilizing mechanical, chemical and biological filtration techniques.
2. Description of the Prior Art
Aquatic life in an aquarium produces waste products and contaminants, such as nitrogenous wastes, fish feces, uneaten food, dead plant materials, etc. These waste products and contaminants are generally removed by filtration. The three basic types of filtration are mechanical, chemical and biological.
Biological filtration is accomplished by aerobic bacteria which colonize a substrate. Gravel provides the greatest amount of surface area for the colonization of bacteria in the aquarium. If oxygenated water is circulated through the gravel, aerobic bacteria will be encouraged and convert the organic waste by-products into less harmful substances. Thus, the gravel bed will function as a biological filter for organic waste products.
Chemical filtration absorbs undesirable gases and other contaminants. Typically, activated carbon is utilized for absorption. Mechanical filtration traps suspended particles. There are many forms of prior art filters which are utilized in the standard aquarium and incorporate one, two or all three of the above described filter types. For example, Malik U.S. Pat. No. 4,312,752 discloses a filter apparatus which mechanically, biologically and chemically filters an aquarium. A pump including an impeller and magnet is provided to circulate water through a filter and dispersion chamber, the filter apparatus being hidden from view; Cloke et al. U.S. Pat. No. 4,035,298 discloses an aquarium filter using mechanical, biological and chemical filtration, an air pump being used for moving water by streams of air directed through the water, rising air bubbles emitted in the main portion of the tank creating a circulation pattern of the water in the tank; and U.S. Pat. No. 4,606,821 to D'Imperio discloses a sectional aquarium having two compartments, an aquarium section with a biological filtering and a mechanical filtering chamber.
The prior art filter systems noted hereinabove provide specific advantages in their use. For example, the Malek system is constructed such that the living area of the aquarium is not obstructed; the Cloke et al patent discloses a filtering apparatus wherein substantially all of the water is continuously moved through the gravel filter bed and uses an air pump to circulate the water, an air pump being less costly than a water pump; and the D'Imperio discloses a system which continuously aerates and filters an aquarium and wherein the actual filter components are hidden from view.
The use of air to circulate water in an aquarium provides an effective and simple way to continuously oxygenate the circulating water. However, foam containing certain organic and inorganic compounds which adhere to the surface of the air bubbles can contaminate the aquarium unless removed, particularly in salt water aquariums. In order to remove this foam, prior art salt water aquariums incorporate a separate device, typically a vertically extending tube and aerator. This obviously increases the cost of salt water aquariums.
What is desired is to provide an air pump driven aquarium filtration system having a reverse flow (water flowing upwards through gravel) and surface skimming wherein the foam containing the organic/inorganic compounds is removed from the aquarium, the filtration system being efficient, easy to maintain and cost effective when compared to prior art systems.